Ingredients
1 large egg
3 tbsp vegetable oil
3 tsp buttermilk
2 tsp vanilla extract
45g caster sugar
2 tbsp unsweetened cocoa powder
45g self-raising flour
Pinch of salt
¼ tsp white wine or cider vinegar
For the topping (optional):
25g butter, really soft
60g icing sugar
1 tsp vanilla extract
30g cream cheese full fat
